Firefly III and Actual are the usual answers here and both are great, worth trying first.
Throwing my own in for transparency since I built it: Finlynq (github.com/finlynq/finlynq, AGPL). Runs on docker + postgres. The differentiator vs firefly/actual is it ships an MCP server, so you can hook up an LLM (Claude, ChatGPT, whatever) and just ask it about your finances or have it log stuff for you. Also does proper multi-currency (stocks/crypto/metals) and encrypts account names at rest.
It’s younger so a smaller community than firefly, being upfront. I’m actively building it and ship often, so if there’s a self-host feature you’d want (specific reverse-proxy setup, backup format, etc) tell me and I’ll prioritize. Demo if you want to click around before pulling the image: finlynq.com/cloud
If it’s specifically portfolio/investments you’re after, Ghostfolio is the popular self-hosted pick and it’s good.
Mine’s another option (disclosure: I’m the dev), Finlynq, AGPL, docker + postgres. It does lot-level cost basis, realized gains by tax year, dividends, and multi-currency with historical FX. Bonus: built-in MCP server so you can ask an AI assistant about the portfolio directly. Self-host or hosted.
Vs ghostfolio it’s broader (full budgeting/accounts too, not just investments) but younger. Actively developed, so if there’s a portfolio feature or broker import you’d need, I can bump it. Repo: github.com/finlynq/finlynq